// Copyright 2019 Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package constraint

import (
	"fmt"
)

// Empty means the collection must be empty.
type Empty struct {
}

var _ Range = &Empty{}

// ValidateItems implements Range
func (e *Empty) ValidateItems(arr []interface{}, p Params) error {
	if len(arr) != 0 {
		return fmt.Errorf("unexpected items found: %+v", arr)
	}
	return nil
}
